IS THE STORY of the double helix also the tale of the double-cross?

The question still lingers like a photo that won’t quite come clear: When three men won the 1962 Nobel Prize for their breakthrough findings on DNA, was it in their genetic makeup not to fully credit the woman in the picture?

The picture at the center of this intrigue is known — with a certain mystery-thriller air — as “Photo 51.” And today, that amazing image gets perhaps its widest single exposure yet: as the ultimate focal point of today’s Google home page.

In the elegant, old-timey Doodle, we see a scientific visionary — even as she sees the very photo that would trigger our sudden understanding of DNA and the swirling, twisted-ladder building blocks of life.

The woman spotlighted is Rosalind Franklin, the pioneering British molecular biologist who wasn’t in the room in real life when her Photo 51 was shared behind her back — and who wasn’t around in death when three colleagues won science’s biggest honor thanks in part to her crucial work.

The brilliant and devoted Franklin should perhaps be known today as science’s “duchess of Cambridge.” Instead, she has been perhaps most widely cast as “the dark lady of DNA” — long rendered as some shadowy figure just outside the frame and field of vision.

It was at Cambridge University during World War II that Franklin focused on physical chemistry, studying graphite and carbon microstructures — she dug intellectually deep into coal — before learning X-ray diffraction in Paris. As an X-ray crystallographer seven years later at King’s College in London, she took the famed “Photo 51” — a 100-hour exposure — that clearly revealed DNA’s double-helix structure.

Since science is also so often about social politics, though, Franklin began to be cut out of history’s picture. She did not get along with her lab’s deputy director, Maurice Wilkins, and — without her knowledge — he showed her Photo 51 to two men who would soon know the white-hot spotlight of scientific glory: American scientist James Watson and British colleague Francis Crick. In her image, they instantly knew what they were seeing, and soon published their groundbreaking DNA discovery in 1953’s Nature journal — according Franklin only a footnote. Her work appeared in that same edition, but only as supporting material.

The 31-year-old Franklin did not openly reveal any bitterness over this, according to lore, and is said to have stayed cordial with glory boys Watson and Crick — even as she moved on, physically and intellectually, to study virology and plants at London’s collegial Birkbeck University.

Tragically, though, Franklin would die a mere five years later, of ovarian cancer. She was just 37. And when history came around for its closeup, just four years after that, the striking London-born daughter of a Jewish merchant was again left out of the picture.

View Photo Gallery: Comic Riffs blog columnist Michael Cavna reveals his favorite Google art.

In 1962, Watson, Crick and Wilkins received the Nobel Prize and the world’s renewed adulation for their work on DNA. The Nobel is not awarded posthumously, however, and Franklin went largely forgotten till 1968, when Watson published his bestselling book “The Double Helix,” and cast “Rosy” (not a nickname she went by) as virtually some frumpy lab villain in his trumped-up dramatic narrative. (Wilkins and Crick aired complaints about his characterizations.)

In the next decade, author Anne Sayre would recast Franklin as a wronged scientific heroine. But the longer arc of history would begin to bend more squarely in Franklin’s favor in 2002, with the publication of Brenda Maddox’s insightful and even-handed biography, “Rosalind Franklin: The Dark Lady of DNA.” (In reviewing the book, Washington Post Book World called it a “complex portrait of a passionate, flawed, courageous woman.”)

The next year, the Royal Society of the UK would establish a Rosalind Franklin Award to honor scientific and technological excellence. And the year after that, one century-old North Chicago institution (adopting Photo 51 as its seal) became the Rosalind Franklin University of Medicine and Science.

Noted Birkbeck chair J.D. Bernal, who write her obituary, once described Franklin’s DNA images as “the most beautiful X-ray photographs of any substance ever taken.” Today, Google celebrates that X-ray beauty, as well as the narrative truth, on what would have been Ms. Franklin’s 93rd birthday.

Crick and Wilkins died in 2004, but Watson — alive and 85 — would finally admit, in Maddox’s book, that glimpsing Photo 51 was a “key event” in their DNA discovery.

Eventually, the bigger picture — like today’s Doodle — tells the fuller story. Thankfully, truth, like a single brilliant DNA photo, is illuminated. .